This is a dog vagina. And this is a dog penis. The penis goes in the vagina; the vagina contracts; the penis fills with blood, creating a bulb that is bigger than the vaginal opening, so then the dog's penis gets locked in there until everything calms down, which can take over an hour. Can't get out, it's locked in!

[Sexplanations intro animation]

Hi, my name is Lindsey. I'm a clinical sexologist and host of this sex-curious show, Sexplanations! This is my dog, Donna. This is Tony. Let's talk about what I've learned about sex from these dogs and 11 other foster pups.

I took Donna and her three 1-week-old puppies in last summer. The humane society who organized everything gave me a kiddie pool, some old sheets, and a bag of puppy food saying "Things won't be too messy at the beginning because the mom will eat their poop to keep things clean."

By that she meant Donna would lick the little puppy assholes and penises so that they'd urinate and defecate right into her mouth. Mmmm, what a mom does to keep a spotless den! It's called coprophagia. Copro -- feces, phagia -- eating, and it's totally normal canine behavior. Which went on for a month, giving me plenty of time to reflect on how this might relate to sex.

Did oral sex evolve from maternal housekeeping? Is coprophilia, the sexual attraction to poop and pooping, caused by diaper changing? Getting your genitals nicely wiped off with the nearby scent of poo? Mmmm...?

I named Donna's puppies Gyri, Sulci, and Myelin, after mispronounced brain anatomy. This is what the little potatoes grew to look like! There's a chihuahua, this fuzzy black guy with a curly tail, and a scraggly dachshund mutt mix? I don't know. None of them look like Mom. But they also don't look like each other. Which could mean heteropaternal superfecundation. Superfecundation! Super-fun-cedation! [laughs] When different dads impregnate different ova, or eggs, from the same mom, so there are twins, triplets, or even an entire litter of puppies that are actually half-siblings. Donna's pups.

Superfecundation is rare in human beings, but it happens. Babies...babies...babies...twins with different daddies!

So I ending up adopting Donna, and we moved here to Baja, Mexico, where I continued to foster many more pups and learned about sexuality from these dogs. I learned, for example, that there are dog STDs.

One, canine herpes, which is like human herpes: it spreads similarly, not typically fatal, but dangerous to newborns. Two: brucellosis, a bacterial infection that's like human chlamydia. It's spread through body fluids and can lead to infertility. A third is canine transmissible venereal tumors, or CTVT. This STD is highly contagious cancer spread through sex, and licking, biting, and sniffing, which causes genitals to kind of explode with cancerous cauliflower-shaped lesions. Ahhhhhh-mmmm... It's similar to our human papillomavirus, which causes cancer, except that we have treatments and surgeries to remove the problem most of the time, and we also have a vaccine that can prevent it. If a dog gets CTVT, the protocol, here at least, is to put it down immediately.

Here are some puppy pictures to clear your mind! Named at the time: Luz, Toast, Mini Toast, Burnt Toast, French Toast, and Lilu Dallas Multipass.

They're all females, because here's something else I've learned about sexuality from having dogs: people here often keep male offspring and get rid of the females. It's part of the machismo that the males protect the families and others rely on them. Mmmm-uuuhhhh [pounds on chest] Arf!

There's a lot of honor, dignity, work ethic, and nurturing that can come from this. Machismo can be a source of caregiving and strength, but it can also be sexist and misogynistic. Mama dogs and female puppies are often abandoned; males are often chained to guard the house. I regularly have to check my ethnocentricity; the way that I'm used pet-loving in the States does not mean that that's the way it is or should be for everyone. Though there is an amazing team here helping to spay and neuter dogs at no cost, get all the puppies into good homes, and educate about shade structures and mobility for the dogs that are chained up. [sighs happily]

This is a picture of Queenie. She has the Playboy bunny on her chest. Did you know that there's a hidden Playboy bunny logo on every cover of the magazine? And it looks like Queenie's marking.

Anyway, I've learned quite a bit about sexuality from Queenie. She was found in very rough shape; the simplest description would be that she was gang-raped. Here's the thing: sex and rape are not the same thing for humans or dogs. There are ways that a female dog positions herself and behaves when she wants to have sex. When she doesn't, she acts differently.

So. We got Queenie all healed up, but then a month or so later it seemed like was pregnant. With big ol' puppies. So we expedited her spay appointment to remove her uterus and abort the fetuses. Which, yes, I was curious about and considered filming, but did not. I didn't want to distract the vet, though he gave me permission. I was confused about the ramifications of what we were doing in a Catholic country, and I was sad to miss out on more puppies, even though I'm very aware that there is an overwhelming number of sick and starving strays. 

Nooo brindle babe. What we came to find out is that Queenie wasn't pregnant at all: she had a six-pound infection from an internal laceration, probably from the raping. Don't worry, she lived.

More puppy pictures! These four came from a brown momma dog named Kahlua, and since she was rescued before having them, I ended up with a male pup -- this gray wolf-looking beauty I named Jamie. The other three girls are Julia, Tony, and Allen, because I appreciate gender-bending.

What I learned from them is that while human testicles typically descend into the scrotum before birth, dog balls drop around two months old. And if they don't, or only one does, this is called cryptorchidism. Crypto -- hidden, orchid -- testicles. Which turns out may be a trait that is passed from generation to generation. That's in dogs and humans. One ball? One ball? Could be from your dad!

There's lots to learn from other species about sexuality. In fact, there are books and videos based on it. Green Porno, by Isabella Rossalini, is a web series where she dresses in elaborate papier-mache as a shrimp, a snail, and many other animals to demonstrate their sexual behaviors. I have the book version. She also has a second series called "Seduce Me" that's more about mating rituals.

I'd also recommend Dr. Tatiana's Sex Advice to All Creation, in which the author, Olivia Judson, acts as an advice columnist for animal sex lives. There's a letter like, "Dear Dr. Tatiana, I'm a queen bee, and I'm worried. All my lovers leave their genitals inside me and then drop dead. Is this normal? Signed, Perplexed in Cloverhill." 

[dogs jumps up on the couch] Ohhh, there you are. Hi, stink-fish-mouth. Woah, baby.

And then she responds with a kind explanation of evolutionary biology that humans can take sex lessons from. 

[rubbing dog's neck] Yeah, you're really showing off!

I would write, "Dear Dr. Tatiana, all of my dogs have been spayed. Are they going to miss out on the pleasure of sex because they no longer go into heat and mate?" "Dear Dr. Tatiana, why don't human penises have a bulbus glandis like dogs' that engorge with blood and lock into the vagina during sex when the vagina contracts? I think this so-called tying or knotting sounds quite nice. Yep, the more I learn, the more curious I become. Staying curious, signed, Mama dog Lindsey."

I've put links to the books I suggested and animal rescue groups in the description if you're interested. Practice having sex doggie-style!

[Sexplanations outro music]

[playing with the toy dog penis & vagina] What is happening!